What about -us?

A mathematical possibility, but the odds are against it.

Angus is the Anglicized spelling of the Scottish Gaelic name Aengus or Aonghus or Aonghas. Unless you have a cultural reason to choose one of the Gaelic variations, Angus is uncommon enough.

Latin for "lamb", and a soundalike of the previously mega-popular female name Agnes, which has long been associated with lambs due to the link. Agnus Dei is Latin for "Lamb of God", honoured within the Catholic Mass and other Christian liturgies.

The ancient name Albus has modern currency as the first name of the headmaster of Harry Potter's Hogwarts, more formally known as Professor Albus Percival Wulfric Brian Dumbledore. Can Albus work if you're missing the long white beard and the magic wand? Maybe, though it might be a heavy mantle for a Muggle child to wear.

This name is a classic example of an underused golden oldie that ticks so many boxes - unusual yet traditional, heaps of cute nicknames, a statement name that exudes retro cool. Aloysius is the Latin form of many more common names like Louis, Luis, Luigi and the uncommon but symphonically familiar Ludwig.

Wolfgang Amadeus Mozart's middle name could make an interesting pick for music-loving parents--if only in middle place. Amadeus is the title of a Peter Shaffer play which became an award-winning film in 1984.

Angus is a traditional yet stylish choice in the UK, especially in Scotland. And it's a cool choice for US parents too, particularly those whose roots go back to Glasgow. The ancient Celtic form Oenghus has important historical overtones in Scotland, and the Gaelic form Aonghas is associated with two distinguished modern poets. In Irish folklore, Angus Og is a chieftain-lord who used his magical powers for the pleasure and prosperity of mankind--and in Irish myth, Aonghus was the god of love and youth.

Astrological name retains a hippielike Age of Aquarius feel.

Variant of Artemas

Atticus, with its trendy Roman feel combined with the upstanding, noble image of Atticus Finch in To Kill a Mockingbird, is a real winner among boy names. Atticus entered the US Top 1000 in 2004 and is a firm Nameberry favorite.

Parents are beginning to look at imposing, somewhat fusty-sounding names like this one with fresh eyes: they definitely make a strong statement.

Since Aurelius was given the supermodel seal of approval by Elle Macpherson, it has joined Augustus as an ancient Roman name that feels usable today. Slightly mystical and magical, Aurelius is grounded by its similarity to rising stars Aurora, Aurelia, and Atticus, and its golden aura is certainly appealing. 

Brutus is the quintessential brute--far too close to the word brutal. And any child with this name would spend much of his life hearing "Et tu."